﻿using System;

class Sheets
{
    static void Main()
    {
        //Telerik Academy Exam 1 @ 27 Dec 2012

        int number = int.Parse(Console.ReadLine());
        int mask = 1;

        for (int i = 0; i <= 10; i++)
        {
            if ((number & mask) == 0)
            {
                Console.WriteLine("A{0}", 10-i);
            }
            mask <<= 1;
        }
       
    }
}

